In aqueous solution, `Li^(+)` ion has the least mobility among alkali metals. Why?

Give reasons for the following: In aqueous solution, Li^+ ion has lowest ionic mobility among all the alkali metals.

In aqueous solution, which alkali metal ion has the lowest mobility?

Assertion : Li^(+) ions has the lowest mobility in aqueous solution Reason : Li^(+) ion has very high ionisation enthalpy.